Making mocks is doing something. I don't think it's healthy for programmers to discount the efforts of designers or vice-versa. Now, it's easy to make mocks that gloss over the real challenges or nasty corner cases, but it's also easy to write garbage code that will never be useful to anyone.

The fact of the matter is that there are a lot of people out there with lots of engineering ability and not much design ability who might jump at the chance of implementing something that's been thoroughly mocked and product-ed out.